Non-small cell lung cancer is a quite common cancer since the annual number of patients and fatalities in Japan are approximately 90,000 (the third largest among malignant cancers) and 65,000 (the leading cause of death among malignant cancers), respectively. Also, the number of patients in the United States and Europe are estimated as 220,000 and 390,000, respectively. The current therapy for non-small cell lung cancer uses an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor. However, patients having T790M point mutation of EGFR are resistant to the EGFR tyrosine kinase inhibitor. About 20% of advanced-stage patients of non-small cell lung cancer have the T790M point mutation. Therefore, effective therapies for the patients with the EGFR tyrosine kinase inhibitor resistance has been required.
EGFR853-861 has been reported as an HLA-A2-restricted antigen peptide derived from the amino acid sequence of EGFR (Non Patent Document 1). However, the peptide is derived from the amino acid sequence of wild-type EGFR, which is an autoantigen, and thus T cells expressing a T cell receptor with high affinity to the peptide has already disappeared due to the selection in thymus (i.e., immune tolerance). Therefore, the peptide is not expected to have a high immunogenicity.